Agreed, especially when the opposition is formed out of several major industries in the country (car manufacturers, adjacent companies, road developers, big box stores, etc.).

I'm not sure it rises to 'opposition' per-se. For instance, I don't think anyone is sitting there cackling about how they're killing anyone due to them being obese fat asses, and figuring out how to make it worse.

It's really macro-economic and social inertia. Those sedentary folks have also convinced themselves they LIKE IT, and there is room (and real economic incentives) in the US trending in those directions. Like low property prices in the 'burbs, cheap gas (by global and economic standards), etc.